Process for making a pellet

ABSTRACT

The invention comprises a shaping process for making pellets of a thermoplastic extrudable resin composition. The resin composition comprises a thermoplastic polymer, plasticiser and optionally further additives. The plasticiser comprises a component which is solid at room temperature. The process is run at a temperature above the melting point of the plasticiser and below the melting/plastification temperature of the thermoplastic polymer.

CROSS-REFERENCE TO RELATED APPLICATION S

This is a continuation application of U.S. patent application Ser. No. 12/949,302, filed 18 Nov. 2010, now U.S. Pat. No. 9,327,425, which is a continuation application of U.S. patent application Ser. No. 10/595,919, filed on 9 Aug. 2006, which is a U.S. National Stage of International Application No. PCT/GB2004/05273, filed 16 Dec. 2004, which claims the benefit of GB 0329529.2, filed 19 Dec. 2003, the entire contents and substance of which are herein hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a process for making pellets of a thermoplastic extrudable polymer.

Processes for making pellets of thermoplastic extrudable polymer are well known in the plastic industry. Typically the pellets are cylindrical and approximately 3 mm in diameter and 3 mm in length. The pellets are used in a wide range of plastic article manufacturing processes.

The pellet manufacturing process generally includes a plastification step. In this step the formulation to be pelletised is melted and fed into a twin screw extruder. This has been seen to be beneficial as the pellets produced have been found to comprise of a homogeneous blend of the pellet components due to effective mixing of all molten components in the extruder.

EP-A-0 415 357 describes the making of pellets comprising polyvinylalcohol (PVOH) by melt extrusion with the extrusion being carried out in the temperature range of 150-195° C.

Pelletising processes having a plastification step have several disadvantages associated therewith. The principle disadvantage is the requirement for heating, which means that the energy consumption of these processes is very high.

Furthermore these “hot” processes are not suitable for polymers which are heat sensitive (such as PVOH) due to heat induced decomposition. Also these “hot” processes give a heat history to the polymer which has been found to negatively influence properties of the polymer. In the case of PVOH this has been found to detrimentally affect the PVOH water solubility.

In other pelletising processes dry compaction of the pellet components is carried out at low temperature. Thus the disadvantages of the “hot” processes are avoided.

WO-A-98/26911 describes a low temperature process for the manufacture of PVOH pellets. In the process the pellets components, in this case a mixture of powdered PVOH and various additives such as plasticisers is fed between two rollers and compressed into pellets. The PVOH component in the pellet blend is not melted in the process and so the issue of heat degradation is avoided.

Also GB-937 057 describes such a low temperature compression process. This follows initial mixing of the plasticiser and PVOH at an elevated temperature. However, although this process (the cold compression process) eliminates the problem of heat induced decomposition of the polymer, the pellets produced suffer from other disadvantages.

Most of the disadvantages stem from the inherent nature of the compaction process, more specifically the rollers and the powder feed thereto. It has been found to be very difficult to ensure that the powder feed is spread evenly across the rollers. This has the effect that control of the size of the pellets is difficult and so the size of the pellets can vary significantly.

Furthermore, significant dust formation is typical for this kind of process. Additionally, the pellets are commonly friable having poor integrity and easily form dust from friction rubbing against each other, thus worsening the dust issue. Both of these issues are attributed to the poor spreading and roller compression technique.

Furthermore, significant variability of the composition of the pellets and poor homogeneity of the pellets has also been observed. The issues are also believed to be associated with the poor powder distribution over the rollers. The problem of the variability of the pellet composition and the poor homogeneity of the pellets is exacerbated when the pellets are taken and used in a further processing step.

These kinds of pellets, wherein the thermoplastic polymer component of the pellets is PVOH, are used in the manufacture of water soluble PVOH pouches in extrusion/injection molding processes. The pouches, as an example, are commonly used to contain a detergent composition for use in an automatic washing machine (laundry/dishwasher). In these applications is it vital that the pellets have high homogeneity to ensure that the pouches produced have good integrity to be stable in storage and have the expected water dissolution properties.

Pellets produced in a cold compaction process, as described above, often fail to meet the level of homogeneity required for the processing into the pouch format.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to obviate/mitigate the problems outlined above. In some embodiments, there is provided a shaping process for making pellets of a thermoplastic extrudable resin composition comprising a thermoplastic polymer, plasticiser and optionally further additives, the plasticiser comprising a component which is solid at room temperature, wherein the process is run at a temperature above the melting point of the plasticiser and below the melting/plastification temperature of the thermoplastic polymer.

In other embodiments, there is provided an extrusion process for making pellets of a thermoplastic extrudable resin composition comprising a thermoplastic polymer, plasticiser and optionally one or more processing aids, the plasticiser comprising a component which is solid at room temperature and which is a carbohydrate selected from the group consisting of: sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt, wherein the maximum temperature of the extrusion process is above the melting point of the plasticiser and below the melting or plastification temperature of the thermoplastic polymer.

In some embodiments, the plasticiser comprises at least 5% wt of the mass of the thermoplastic extrudable resin composition. In other embodiments, the plasticiser comprises at least 10% wt of the mass of the thermoplastic extrudable resin composition. In further embodiments, the plasticiser comprises at least 15% wt of the mass of the thermoplastic extrudable resin composition.

In some embodiments, the particle size of raw materials used is below 2000 μm.

In some embodiments, the thermoplastic polymer is water-soluble or water dispersible. In certain aspects, the thermoplastic polymer comprises PVOH or a derivative thereof. In other aspects, the thermoplastic polymer comprises: poly(vinylpyrollidone), poly(acrylic acid), poly(maleic acid), a cellulose derivative, poly(glycolide), poly(glycolic acid), poly(lactides), poly(lactic acid) and copolymers thereof.

In some embodiments of the present invention, the temperature of the thermoplastic extrudable resin composition within the extruder does not exceed a temperature which is 10° C. below the melting or plastification temperature of the thermoplastic polymer. In other embodiments, said temperature does not exceed a temperature which is 15° C. below the melting or plastification temperature of the thermoplastic polymer. In still other embodiments, said temperature does not exceed a temperature which is 30° C. below the melting or plastification temperature of the thermoplastic polymer.

In some embodiments, the temperature within the extruder is at least 40° C. In other embodiments, the temperature within the extruder is at least 50° C.

In another aspect of the invention is provided an extrusion process for making pellets of a thermoplastic extrudable resin composition consisting of a thermoplastic polymer, plasticizer and optionally one or more processing aids, the plasticiser comprising a component which is solid at room temperature and which is a carbohydrate selected from the group consisting of: sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt, wherein the maximum temperature of the extrusion process is above the melting point of the plasticizer and below the melting or plastification temperature of the thermoplastic polymer.

In another aspect of the invention is provided a process of manufacturing an injection molded water soluble pouch containing a detergent formulation, said method comprising the steps of injection molding a water soluble pouch from pellets of a thermoplastic extrudable resin composition formed by an extrusion process for making the pellets of a thermoplastic extrudable resin composition comprising a thermoplastic polymer, plasticiser and optionally one or more processing aids, the plasticiser comprising a component which is solid at room temperature and which is a carbohydrate selected from the group consisting of: sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt, wherein the maximum temperature of the extrusion process is above the melting point of the plasticiser and below the melting or plastification temperature of the thermoplastic polymer.

In any of the above embodiments, the one or more processing aids are selected from: mono-, di-, tri-carboxylic acids/salts thereof, fatty acids, mono-, di-, and tri glycerides/salts thereof, aerosol, inorganic pigments and organic pigments.

In any of the above embodiments, water is excluded from the process.

DETAILED DESCRIPTION OF THE INVENTION

To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or examples. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the exemplary embodiments, specific terminology will be resorted to for the sake of clarity.

It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named. In other words, the terms “a,” “an,” and “the” do not denote a limitation of quantity, but rather denote the presence of “at least one” of the referenced item.

Also, in describing the exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value. Further, the term “about” means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, “about” can mean within an acceptable standard deviation, per the practice in the art. Alternatively, “about” can mean a range of up to ±20%, preferably up to ±10%, more preferably up to ±5%, and more preferably still up to ±1% of a given value. Alternatively, particularly with respect to biological systems or processes, the term can mean within an order of magnitude, preferably within 2-fold, of a value. Where particular values are described in the application and claims, unless otherwise stated, the term “about” is implicit and in this context means within an acceptable error range for the particular value.

By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

Throughout this description, various components may be identified having specific values or parameters, however, these items are provided as exemplary embodiments. Indeed, the exemplary embodiments do not limit the various aspects and concepts of the present invention as many comparable parameters, sizes, ranges, and/or values may be implemented. The terms “first,” “second,” and the like, “primary,” “secondary,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

It is noted that terms like “specifically,” “preferably,” “typically,” “generally,” and “often” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention. It is also noted that terms like “substantially” and “about” are utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “50 mm” is intended to mean “about 50 mm.”

It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified.

The materials described hereinafter as making up the various elements of the present invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, materials that are developed after the time of the development of the invention, for example.

According to the present invention there is provided a shaping process for making pellets of a thermoplastic extrudable resin composition comprising a thermoplastic polymer, plasticiser and optionally further additives, the plasticiser comprising a component which is solid at room temperature, wherein the process is run at a temperature above the melting point of the plasticiser and below the melting/plastification temperature of the thermoplastic polymer.

The shaping process may comprise pressing, extrusion, calendering and/or compaction. Most preferably the shaping process comprises extrusion.

The process of the present invention has been found to overcome the disadvantages associated with the prior art. Firstly as the process is operated at a temperature below the melting/plastification temperature of the thermoplastic polymer the process has been found to be extremely energy efficient. Furthermore the heat degradation of heat sensitive materials in the resin blend is dramatically reduced by the lowered process temperatures.

Additionally as the process operates above the melting point of the plasticiser (which is then allowed to cool to form the solid pellet) the pellets have been found to have a very low friability. Thus the pellets have a much lower tendency to release dust upon friction rubbing.

Furthermore as the pellets are produced at a temperature above the melting point of the plasticiser component the pellets have been found to have excellent homogeneity. More specifically both the overall composition of each pellet and the distribution of the individual components within the pellets have been found to have a high level of predictability and low variance. This is especially important when the pellets are used in a further processing step such as a second extrusion process (e.g., injection molding) for the manufacture of an article comprising the thermoplastic polymer.

Generally the components are delivered to the shaping equipment used in the process in particulate form.

It has been found that the particle size of the raw materials used to make the pellets should be small. This has been observed to ensure high homogeneity of the pellets. The particle size of the raw materials used preferably is below 2000 μm, more preferably below 1200 μm, more preferably below 400 μm and most preferably about 200 μm.

Preferably the plasticiser is present in the composition with at least 5%, more preferably 10%, most preferably 15%.

Preferably the temperature of the material within the extruder does not exceed a temperature which is 10° C. below the melting/plastification temperature of the thermoplastic polymer at any time. More preferably it does not exceed 15° C., more preferably 30° C. and most preferably 45° C. below the melting/plastification temperature of the thermoplastic polymer. However, it is desired that the temperature of the material exceeds the ambient air temperature. Preferably the temperature of material within the extruder is at least 40° C., more preferably at least 45° C., and most preferably at least 50° C.

The plasticiser has to at least partially melt at the preferred operating temperature. The melting point of the plasticiser component is preferably at least 15° C., preferably at least 30° C. and most preferably at least 45° C. below the melting/plastification temperature of the thermoplastic polymer.

Preferably the plasticiser comprises a carbohydrate.

Carbohydrates are usually represented by the generalized formula C_(x)(H₂O)_(y). The term herein also includes materials which are similar in nature like gluconic acids or amino sugars which cannot be fully represented by this formula. Other carbohydrate derivatives like sugar alcohols such as sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt fall within this term.

Most preferred carbohydrates include the more thermally stable carbohydrates such as sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt.

Other preferred plasticiser systems include solid fatty acid alkoxylates, fatty alcohol alkoxylates or polyalkylene glycols (such as long chain polyethylene glycol).

The plasticiser may comprise a further auxiliary component. Preferred auxiliary components include glycerin, ethylene glycol, propylene glycol, diethylene glycol, diproylene glycol, triethanol amine, diethanol amine and methyldiethyl amine.

Once the one or more strands have issued from the extruder it may be permitted to cool under ambient conditions. Alternatively cooling may be assisted. One way in which this may be done is by employing a cooled metal belt onto which the one or more strands issue. Another way in which this may be done is by using a cooled fluid, preferably cooled air, downstream of the extruder. Another way is by blowing a fluid, preferably air, across the one or more strands. One or more of these methods may be used.

Preferably the one or more strands are separated into pellets, during the manufacture.

The strands are separated into pellets preferably by cutting. However, other separation methods, for example twisting, are not ruled out. A method may be envisaged whereby the strand is twisted at intervals when still plastic, to form “sausages”, which can be separated by breaking the connections, once they have become more brittle. Partial cutting or pressing or nipping or perforating (all such methods collectively called “scoring” herein) to form frangible separation webs, may also be employed, to form tablet precursors. Separation of the precursors to produce pellets may be effected during manufacture or by the consumer, manageable lengths being provided from which the consumer breaks or twists off pellets as required. A pellet precursor may be, for example, a straight row of pellets, to be broken off as needed.

The extrusion pressure may be whatever is required to carry out the process in an efficient manner. Suitably it is in excess of 3 bar (0.3 MPa), preferably in excess of 5 bar (0.5 MPa), and more preferably is preferably in excess of 8 bar (0.8 MPa). More preferably still is preferably in excess of 12 bar (1.2 MPa). Most preferably it is in excess of 40 bar (4 MPa). The extrusion pressure preferably does not exceed 100 bar (10 MPa), more preferably 60 bar (6 MPa).

Generally the pellets are for use in injection molding processes. The injection molding process is preferably used for the manufacture of water soluble pouches intended to contain a detergent formulation for use in an automatic washing machine or in an automatic dishwasher. Thus the pellets preferably comprising a water-soluble/water-dispersible thermoplastic polymer.

In this use the advantageous properties of the pellets produced in accordance with the invention, especially the high homogeneity have been found to be particularly beneficial. It is believed that this property is most beneficial as the integrity of the injection molded product relies upon such high homogeneity of the composition being injection molded as otherwise the low homogeneity will be reflected in the injection molded product. The high homogeneity has been found to lead to predictable water solubility of injection molded products.

Preferably the water-soluble/water-dispersible thermoplastic polymer comprises PVOH or a derivative thereof.

Other water-soluble/water-dispersible polymers may be used in the process either as an alternative or in addition to PVOH. Preferred examples include poly(vinylpyrollidone), poly(acrylic acid), poly(maleic acid), a cellulose derivative (such as a cellulose ether/hydroxypropyl methyl cellulose), poly(glycolide), poly(glycolic acid), poly(lactides), poly (lactic acid) and copolymers thereof.

Processing aids may be present in the admixture which is processed. Preferred processing aids include mono-, di-, tri-carboxylic acids/salts thereof, fatty acids such as stearic acid/salts thereof, mono-, di- or triglycerides/salts thereof, aerosil, inorganic and organic pigments.

The invention will now be illustrated with reference to the following non-limiting Examples.

EXAMPLES

The present invention is also described and demonstrated by way of the following examples. However, the use of these and other examples anywhere in the specification is illustrative only and in no way limits the scope and meaning of the invention or of any exemplified term Likewise, the invention is not limited to any particular preferred embodiments described here. Indeed, many modifications and variations of the invention may be apparent to those skilled in the art upon reading this specification, and such variations can be made without departing from the invention in spirit or in scope. The invention is therefore to be limited only by the terms of the appended claims along with the full scope of equivalents to which those claims are entitled.

Example 1

The pelletising process was conducted on an extruder (twin screw, ICMA S. Giorgio, Milan (dedicated to processing of plastic blends and alloys).

The extruder had the following characteristics.

-   -   Screw diameter: 35 mm     -   Screw length: 40 cm     -   Working pressure: 30 bar     -   Output: 5 kg/h.     -   Temperature zones: 6 (T1=50° C., T2=60° C., T3=T4=90° C.,         T5=105° C. and T6 (the die)=105° C.)

The extruder was attached to a two-roll unit used as a cooling source and connected to a pellet cutter.

The following formula was fed into the extruder in powder form.

Material % PVOH resin 85.0 Sorbitol 11.0 Processing aids 4.0 Total 100.0

The pellets obtained were chilled to room temperature. The formula yielded solid pellets having low friability.

Example 2

The pelletising process was conducted on a pellet press (model V3-75 from Universal Milling Technologies).

The press had the following characteristics.

-   -   Die diameter: 350 mm     -   Holes diameter: 2 mm     -   Hole length: 3 mm     -   Infeed cone: 45°     -   Space between die/rollers: 1.5 mm     -   Die speed: 5 m/s     -   Motor: 30 kW     -   Temperature: 98-102° C.

The following formulae were fed into the extruder in powder form.

Material Formula 1 Formula 2 Formula 3 PVOH resin 81.0 87.0 85.0 Sorbitol 15.0 11.0 11.0 Processing aids 4.0 2.0 4.0 Total 100.0 100.0 100.0

The pellets obtained were chilled to room temperature. Each formula yielded solid pellets having low friability.

While several possible embodiments are disclosed above, embodiments of the present invention are not so limited. These exemplary embodiments are not intended to be exhaustive or to unnecessarily limit the scope of the invention, but instead were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims. Further, the terminology employed herein is used for the purpose of describing exemplary embodiments only and the terminology is not intended to be limiting since the scope of the various embodiments of the present invention will be limited only by the appended claims and equivalents thereof. The scope of the invention is therefore indicated by the following claims, rather than the foregoing description and above-discussed embodiments, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.

Disclosed are methods and compositions that can be used for, can be used in conjunction with, can be used in preparation for, or are products of the disclosed methods and compositions. These and other materials are disclosed herein, and it is understood that combinations, subsets, interactions, groups, etc. of these methods and compositions are disclosed. That is, while specific reference to each various individual and collective combinations and permutations of these compositions and methods may not be explicitly disclosed, each is specifically contemplated and described herein. For example, if a particular composition of matter or a particular method is disclosed and discussed and a number of compositions or methods are discussed, each and every combination and permutation of the compositions and the methods are specifically contemplated unless specifically indicated to the contrary. Likewise, any subset or combination of these is also specifically contemplated and disclosed.

All patents, applications, publications, test methods, literature, and other materials cited herein are hereby incorporated by reference in their entirety as if physically present in this specification. 

What is claimed is:
 1. An extrusion process for making pellets of a thermoplastic extrudable resin composition comprising a thermoplastic polymer, plasticiser and optionally one or more processing aids, the plasticiser comprising a component which is solid at room temperature and which is a carbohydrate selected from the group consisting of: sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt, wherein the maximum temperature of the extrusion process is above the melting point of the plasticiser and below the melting or plastification temperature of the thermoplastic polymer.
 2. The process according to claim 1, wherein the plasticiser comprises at least 5% wt of the mass of the thermoplastic extrudable resin composition.
 3. The process according to claim 2, wherein the plasticiser comprises at least 10% wt of the mass of the thermoplastic extrudable resin composition.
 4. The process according to claim 3, wherein the plasticiser comprises at least 15% wt of the mass of the thermoplastic extrudable resin composition.
 5. The process according to claim 1, wherein the particle size of raw materials used is below 2000 μm.
 6. The process according to claim 1, wherein the thermoplastic polymer is water-soluble or water dispersible.
 7. The process according to claim 6, wherein the thermoplastic polymer comprises PVOH or a derivative thereof.
 8. The process according to claim 1, wherein the thermoplastic polymer comprises: poly(vinylpyrollidone), poly(acrylic acid), poly(maleic acid), a cellulose derivative, poly(glycolide), poly(glycolic acid), poly(lactides), poly(lactic acid) and copolymers thereof.
 9. The process according to claim 1, wherein the temperature of the thermoplastic extrudable resin composition within the extruder does not exceed a temperature which is 10° C. below the melting or plastification temperature of the thermoplastic polymer.
 10. The process according to claim 9, wherein the temperature of the thermoplastic extrudable resin composition within the extruder does not exceed a temperature which is 15° C. below the melting or plastification temperature of the thermoplastic polymer.
 11. The process according to claim 10, wherein the temperature of the thermoplastic extrudable resin composition within the extruder does not exceed a temperature which is 30° C. below the melting or plastification temperature of the thermoplastic polymer.
 12. The process according to claim 1, wherein the temperature within the extruder is at least 40° C.
 13. The process according to claim 1, wherein the temperature within the extruder is at least 50° C.
 14. An extrusion process for making pellets of a thermoplastic extrudable resin composition consisting of: a thermoplastic polymer, plasticizer and optionally one or more processing aids, the plasticiser comprising a component which is solid at room temperature and which is a carbohydrate selected from the group consisting of: sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt, wherein the maximum temperature of the extrusion process is above the melting point of the plasticizer and below the melting or plastification temperature of the thermoplastic polymer.
 15. A process of manufacturing an injection molded water soluble pouch containing a detergent formulation, the method comprising the steps of: injection molding a water soluble pouch from pellets of a thermoplastic extrudable resin composition formed by an extrusion process for making the pellets of a thermoplastic extrudable resin composition comprising a thermoplastic polymer, plasticiser and optionally one or more processing aids, the plasticiser comprising a component which is solid at room temperature and which is a carbohydrate selected from the group consisting of: sorbitol, glucitol, mannitol, galactitol, dulcitol, xylitol, erythritol, isomaltutose and isomalt, wherein the maximum temperature of the extrusion process is above the melting point of the plasticiser and below the melting or plastification temperature of the thermoplastic polymer.
 16. The process according to claim 1 wherein the one or more processing aids are selected from: mono-, di-, tri-carboxylic acids/salts thereof, fatty acids, mono-, di-, and tri glycerides/salts thereof, aerosol, inorganic pigments and organic pigments.
 17. The process according to claim 1, wherein water is excluded from the process.
 18. The process according to claim 14, wherein water is excluded from the process.
 19. The process according to claim 15, wherein water is excluded from the process. 